Immunocytochemical Localization of a Wheat Germ Lysozyme in Wheat Embryo and Coleoptile Cells and Cytochemical Study of Its Interaction with the Cell Wall

Abstract

Among several wheat (Triticum aestiyum L.) germ proteins able to lyse Micrococcus lysodeikticus, one lysozyme (WI A) was purified by ionexchange chromatography, gel filtration, and preparative polyacrylamide gel electrophoresis. Polyclonal antibodies against this lysozyme were raised in rabbits. The in situ localization of WlA lysozyme was achieved by the indirect protein A-gold technique. Large amounts of WIA lysozyme were found in cell walls whereas intercellular spaces, cytoplasm, and organelles were nearly free of labeling. Specificity of labeling was assessed with several controls. In an attempt to detect the presence of binding sites, WlA lysozyme was complexed to colloidal gold. Particles were specifically distributed in large amounts over wheat embryo and coleoptile cell walls. The absence of labeling over isolated coleoptile cell walls treated with 0.1 and 0.4 molar potassium hydroxide for hemicellulose extraction indicated that WlA lysozyme binding sites were probably of hemicellulosic nature.

Can lysozymes mediate antibacterial resistance in plants?

“…Lysozyme activities have been detected in various plant species [1,2,8,19,21,27,43,44]. Most of the plant lysozymes are bifunctional enzymes displaying a much stronger chitinase than lysozyme function [23 ].…”

“…The subcellular location of plant lysozymes has been investigated at electron microscopic level for a wheat germ lysozyme [1] and basic lysozyme/ chitinases from bean [33] as well as by biochemical methods for those from bean [3], tobacco [47] and tobacco and petunia [29]. The wheat germ lysozyme has been localized in cell walls only but neither in cytoplasm nor in intercellular spaces.…”

“…The bacteriolytic in vitro activity of different lysozymes from various organisms is well known for a long time. Also in several plant species the presence of lysozymes has been detected in recent years [ 1,2,8,19,21,27,43,44]. Yet, an involvement of endogenous plant lysozymes in plant-bacteria interactions has not been demonstrated until now.…”

Influence of transgenic T4-lysozyme-producing potato plants on potentially beneficial plant-associated bacteria

“…In these experiments the sensitivity of bacteria was also observed in the absence of the chelating agent EDTA [10]. Bacteriophage T4‐lysozyme is the most active member of a class of bacteriolytic enzymes, which have been detected in several plant species [11,12]. The secretion of foreign T4‐lysozyme into the intercellular spaces of transgenic potato plants affects resistance against Erwinia carotovora already at relatively low levels of expression [13].…”

Creation of Transgenic Bananas Expressing Human Lysozyme Gene for Panama Wilt Resistance

“…It is well known that lysozymes play protective and defensive roles against bacterial or fungal pathogens in many organisms. The introduction of lysozymes to improve the disease resistance of crops has been reported previously (Audy et al 1988). Human lysozyme (HL) is a biofunctional enzyme, which can cleave the β-(1-4) glycosidic bond of peptidoglycan in the bacterial cell wall and of chitin in the fungal cell wall.…”